Interleukin-27-adipose-derived mesenchymal stromal cell-based gene therapy attenuates inflammation in lipopolysaccharide-induced acute respiratory distress syndrome.

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a lung inflammatory condition associated with the accumulation of fluid edema and cell infiltrates into the alveolar space along with dysregulation of the immune response. Current therapeutics are limited to palliative care, i.e., mechanical ventilators, thus highlighting the need to develop targeted therapeutic for ARDS. Interleukin-27 (IL-27) is a multifunctional cytokine with the capability for immune modulation. Our interest lies in exploring the properties of IL-27, particularly as an anti-inflammatory cytokine that functions as an antagonist of IL-6 signaling, as an inducer of anti-viral genes, as a promoter of tissue repair, and as a regulator of both the innate and adaptive immune responses, possessing promising potential as a therapeutic for ARDS.

METHODS

To overcome the challenge of repeated administration due to the short half-life of cytokines, we utilized a cell-based gene therapy approach. An IL-27-expressing plasmid was transfected into adipose mesenchymal stromal cells (ASC) that serve as the gene therapy carriers. For in vitro studies, we treated mono- and co-culture lung lipopolysaccharide (LPS)-induced lung epithelial and monocytes/macrophages cell line with IL-27-expressing ASC (IL-27 ASC) conditioned media (CM) to determine the effects on pro-inflammatory gene expression. For in vivo studies, male C57BL/6 mice were intratracheally injected with LPS (5 mg/kg) and treated either PBS, ASC, or IL-27 ASC (5 × 105 cells/mouse) 24 h after LPS instillation. Measurements of gene expression, histopathological changes, cell infiltrations, and protein content in the bronchoalveolar lavage fluid and RNA-seq analysis were performed for the in vivo studies.

RESULTS

IL-27 ASC CM reduced pro-inflammatory gene expression of lung epithelial and macrophages cultured in both mono- and co-culture systems. Additionally, IL-27 ASC were able to reduce pro-inflammatory markers, decrease cell infiltration into the lungs, promote genes and immune cells involved in tissue repair, and rebalance innate and adaptive immunity in an LPS-induced in vivo model.

CONCLUSIONS

Collectively, our in vitro and in vivo results show promising potential for IL-27 cell-based gene therapy as a treatment for ARDS.